Engineering Lead | Remote & Async

Scale data systems that handle billions

At Koinly, we’re looking for an Engineering Lead (also known in some companies as a Tech Lead) who’s at their best scaling high-volume systems, optimizing databases, and digging deep into performance bottlenecks while guiding a small senior team.

This role is hands-on ~80% of the time, with ~20% focused on leadership, technical direction, and mentoring. We’re looking for someone who loves optimizing high-volume systems, tuning databases, and guiding senior engineers without getting buried in management overhead.

Our backend is pure Ruby on Rails, built by engineers who care deeply about craft, speed, and impact. You’ll work directly with our founder (also a Ruby and Rails engineer) in a culture that values autonomy, deep work, and zero bureaucratic bloat.

We’re a fully remote-first, async-first startup with product-market fit in a niche (and booming) domain: crypto taxes. If you value autonomy, technical excellence, and clear communication over meetings and process complexity, Koinly is the place for you.

What you’ll do

Own and evolve the architecture and performance of our Ruby + PostgreSQL backend, processing billions (and billions) of records daily.

Design, build, and run large-scale, high-performance data platforms engineered for low latency and high availability.

Profile, tune, and squeeze every millisecond from systems that handle billions (and billions) of records across 900+ integrations.

Drive technical excellence by setting best practices, design patterns, and coding standards.

Review and approve technical designs and pull requests.

Support and empower your team of 5 senior engineers while staying ~80% hands-on.

Lead and guide debates to help reach consensus; once a decision is made, clearly communicate it back.

Collaborate across the project lifecycle: requirements, design, prototype, implementation, review, release, monitoring.

Collaborate async with product, design, marketing, and leadership to move fast without the meetings.

Contribute to the development and planning of our core roadmap.

Stay ahead of emerging trends to drive continuous improvement.

Help scale our platform used globally by crypto investors, traders, and tax professionals.

What you bring

Proven experience building and maintaining data-intensive, large-scale, high-performance platforms.

Track record of solving performance bottlenecks and working with structured data at scale.

Strong expertise in Ruby/Ruby on Rails.

Deep understanding of data engineering principles: data modeling, ETL pipelines, stream processing.

Experience with CI/CD pipelines, infrastructure as code (IaC), and monitoring tools.

Comfortable with 80% hands-on coding alongside leadership responsibilities.

Happy in an async-first environment.

Experience with high-volume systems, performance bottlenecks, and structured data.

Comfortable leading without layers: influencing direction without managing people full-time.

Happy working async with a globally distributed team.

Bonus points if you’ve:

Tuned Postgres.

Debugged deadlocks or handled race conditions at scale.

Designed or scaled ingestion pipelines with messy external data.

Worked in domains like fintech, taxtech, martech, or open banking.

Knowledge of blockchain protocols, smart contracts, and DeFi.

Why join Koinly

A profitable, bootstrapped startup in a hyper-growth industry.

Direct access to the founder, an engineer who understands your challenges.

Pure Ruby on Rails backend, no language sprawl, no over-engineering.

High autonomy, async-first, deep work, minimal meetings.

Massive data volume: billions (and billions) of trades, 900+ integrations.

Lean team with big impact: millions of users, only 37 people company-wide.

No bureaucratic bloat, no corporate theatre.

Remote, flexible working hours, async by default.

Crypto-adjacent without the hype: we’re a painkiller, not a multivitamin.

Compensation and location

Salary range: USD $100K-120K per year

Contract type: Full-time (Contractor - B2B)

Location: Remote [EMEA]

Perks:

32 days of PTO

Async culture

Fast-moving team

Founder access

The expectation that you own your work

If you love scaling high-volume systems, optimizing databases, and staying hands-on while leading, this role is for you. Apply now!

Key details in sum

Report to: Engineering Manager

Location: Remote - preference for Europe-based candidates

Salary: USD $100k-$120k per year

Type: Full-time (contractor - B2B)

Experience level: Senior (+7 years) with prior leadership experience

Start date: ASAP

Team size: 4-5 directs within a 10 person engineering team

Main responsibilities: Lead and scale a high-performance Ruby + PostgreSQL backend, driving architecture, team excellence, and cross-functional collaboration to power a global crypto data platform.